Mystery mysterious of polygons on Pluto

03.06.2016

Two groups of scientists, one of which is Purdue University and the second a number of other American universities, could explain the previously discovered features of the topography of Pluto. Earlier automatic interplanetary stationNew Horizons on the surface of the dwarf planet were recorded polygonal cells. As it turned out, they were formed as a result of convection.

photo: ru.wikipedia.org

Unusual polygons reaches a length on average of about a kilometre, and professionals immediately it was obvious that they were definitely not as a result of and even against the impact of meteorites. However, the true reason for their appearance for some time remained unknown. In two new studies concurrently published in the journal Nature, researchers presented evidence that this reason might be the phenomenon called “convection Rayleigh — Benard”. This means that the polygons of nitrogen ice become so influenced by the internal heat of the dwarf planet.

The temperature on Pluto is much lower than on Earth, so the melting of the water ice under the influence of internal heat, it hardly seems possible. At the same time, the nitrogen returns to the liquid state when the temperature is -236 degrees Celsius, is much more achievable in terms of Pluto.

At the points where nitrogen ice is heated by the decay of long-lived radioactive isotopes in the earth, it melts and moves to the surface, where it refreezes and turns into a solid state. Such a cycle leads, in particular, to the fact that the traces left falling on a surface polygons by the meteors, gradually “are tightened”. A complete upgrade of the surface of the ice structures is happening on a cosmic scale, very quickly — in about half a million years.

The results obtained, in particular, help explain why some Kuiper belt objects are unexpectedly bright — if they also occur similar processes, their surface is covered with fresh ice, so to reflect light better than if the ice gave way and covered with dust.